src/login/logind-core.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/ioctl.h>
   5 #include <sys/types.h>
   6 #include <linux/vt.h>
   7
   8 #include "sd-device.h"
   9
  10 #include "alloc-util.h"
  11 #include "bus-error.h"
  12 #include "bus-util.h"
  13 #include "cgroup-util.h"
  14 #include "conf-parser.h"
  15 #include "device-util.h"
  16 #include "efi-loader.h"
  17 #include "errno-util.h"
  18 #include "fd-util.h"
  19 #include "limits-util.h"
  20 #include "logind.h"
  21 #include "parse-util.h"
  22 #include "path-util.h"
  23 #include "process-util.h"
  24 #include "stdio-util.h"
  25 #include "strv.h"
  26 #include "terminal-util.h"
  27 #include "udev-util.h"
  28 #include "user-util.h"
  29 #include "userdb.h"
  30 #include "utmp-wtmp.h"
  31
  32 void manager_reset_config(Manager *m) {
  33         assert(m);
  34
  35         m->n_autovts = 6;
  36         m->reserve_vt = 6;
  37         m->remove_ipc = true;
  38         m->inhibit_delay_max = 5 * USEC_PER_SEC;
  39         m->user_stop_delay = 10 * USEC_PER_SEC;
  40
  41         m->handle_power_key = HANDLE_POWEROFF;
  42         m->handle_power_key_long_press = HANDLE_IGNORE;
  43         m->handle_reboot_key = HANDLE_REBOOT;
  44         m->handle_reboot_key_long_press = HANDLE_POWEROFF;
  45         m->handle_suspend_key = HANDLE_SUSPEND;
  46         m->handle_suspend_key_long_press = HANDLE_HIBERNATE;
  47         m->handle_hibernate_key = HANDLE_HIBERNATE;
  48         m->handle_hibernate_key_long_press = HANDLE_IGNORE;
  49
  50         m->handle_lid_switch = HANDLE_SUSPEND;
  51         m->handle_lid_switch_ep = _HANDLE_ACTION_INVALID;
  52         m->handle_lid_switch_docked = HANDLE_IGNORE;
  53
  54         m->power_key_ignore_inhibited = false;
  55         m->suspend_key_ignore_inhibited = false;
  56         m->hibernate_key_ignore_inhibited = false;
  57         m->lid_switch_ignore_inhibited = true;
  58         m->reboot_key_ignore_inhibited = false;
  59
  60         m->holdoff_timeout_usec = 30 * USEC_PER_SEC;
  61
  62         m->idle_action_usec = 30 * USEC_PER_MINUTE;
  63         m->idle_action = HANDLE_IGNORE;
  64
  65         m->runtime_dir_size = physical_memory_scale(10U, 100U); /* 10% */
  66         m->runtime_dir_inodes = DIV_ROUND_UP(m->runtime_dir_size, 4096); /* 4k per inode */
  67         m->sessions_max = 8192;
  68         m->inhibitors_max = 8192;
  69
  70         m->kill_user_processes = KILL_USER_PROCESSES;
  71
  72         m->kill_only_users = strv_free(m->kill_only_users);
  73         m->kill_exclude_users = strv_free(m->kill_exclude_users);
  74
  75         m->stop_idle_session_usec = USEC_INFINITY;
  76 }
  77
  78 int manager_parse_config_file(Manager *m) {
  79         assert(m);
  80
  81         return config_parse_many_nulstr(
  82                         PKGSYSCONFDIR "/logind.conf",
  83                         CONF_PATHS_NULSTR("systemd/logind.conf.d"),
  84                         "Login\0",
  85                         config_item_perf_lookup, logind_gperf_lookup,
  86                         CONFIG_PARSE_WARN, m,
  87                         NULL);
  88 }
  89
  90 int manager_add_device(Manager *m, const char *sysfs, bool master, Device **ret_device) {
  91         Device *d;
  92
  93         assert(m);
  94         assert(sysfs);
  95
  96         d = hashmap_get(m->devices, sysfs);
  97         if (d)
  98                 /* we support adding master-flags, but not removing them */
  99                 d->master = d->master || master;
 100         else {
 101                 d = device_new(m, sysfs, master);
 102                 if (!d)
 103                         return -ENOMEM;
 104         }
 105
 106         if (ret_device)
 107                 *ret_device = d;
 108
 109         return 0;
 110 }
 111
 112 int manager_add_seat(Manager *m, const char *id, Seat **ret_seat) {
 113         Seat *s;
 114         int r;
 115
 116         assert(m);
 117         assert(id);
 118
 119         s = hashmap_get(m->seats, id);
 120         if (!s) {
 121                 r = seat_new(&s, m, id);
 122                 if (r < 0)
 123                         return r;
 124         }
 125
 126         if (ret_seat)
 127                 *ret_seat = s;
 128
 129         return 0;
 130 }
 131
 132 int manager_add_session(Manager *m, const char *id, Session **ret_session) {
 133         Session *s;
 134         int r;
 135
 136         assert(m);
 137         assert(id);
 138
 139         s = hashmap_get(m->sessions, id);
 140         if (!s) {
 141                 r = session_new(&s, m, id);
 142                 if (r < 0)
 143                         return r;
 144         }
 145
 146         if (ret_session)
 147                 *ret_session = s;
 148
 149         return 0;
 150 }
 151
 152 int manager_add_user(
 153                 Manager *m,
 154                 UserRecord *ur,
 155                 User **ret_user) {
 156
 157         User *u;
 158         int r;
 159
 160         assert(m);
 161         assert(ur);
 162
 163         u = hashmap_get(m->users, UID_TO_PTR(ur->uid));
 164         if (!u) {
 165                 r = user_new(&u, m, ur);
 166                 if (r < 0)
 167                         return r;
 168         }
 169
 170         if (ret_user)
 171                 *ret_user = u;
 172
 173         return 0;
 174 }
 175
 176 int manager_add_user_by_name(
 177                 Manager *m,
 178                 const char *name,
 179                 User **ret_user) {
 180
 181         _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
 182         int r;
 183
 184         assert(m);
 185         assert(name);
 186
 187         r = userdb_by_name(name, USERDB_SUPPRESS_SHADOW, &ur);
 188         if (r < 0)
 189                 return r;
 190
 191         return manager_add_user(m, ur, ret_user);
 192 }
 193
 194 int manager_add_user_by_uid(
 195                 Manager *m,
 196                 uid_t uid,
 197                 User **ret_user) {
 198
 199         _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
 200         int r;
 201
 202         assert(m);
 203         assert(uid_is_valid(uid));
 204
 205         r = userdb_by_uid(uid, USERDB_SUPPRESS_SHADOW, &ur);
 206         if (r < 0)
 207                 return r;
 208
 209         return manager_add_user(m, ur, ret_user);
 210 }
 211
 212 int manager_add_inhibitor(Manager *m, const char* id, Inhibitor **ret) {
 213         Inhibitor *i;
 214         int r;
 215
 216         assert(m);
 217         assert(id);
 218
 219         i = hashmap_get(m->inhibitors, id);
 220         if (!i) {
 221                 r = inhibitor_new(&i, m, id);
 222                 if (r < 0)
 223                         return r;
 224         }
 225
 226         if (ret)
 227                 *ret = i;
 228
 229         return 0;
 230 }
 231
 232 int manager_add_button(Manager *m, const char *name, Button **ret_button) {
 233         Button *b;
 234
 235         assert(m);
 236         assert(name);
 237
 238         b = hashmap_get(m->buttons, name);
 239         if (!b) {
 240                 b = button_new(m, name);
 241                 if (!b)
 242                         return -ENOMEM;
 243         }
 244
 245         if (ret_button)
 246                 *ret_button = b;
 247
 248         return 0;
 249 }
 250
 251 int manager_process_seat_device(Manager *m, sd_device *d) {
 252         Device *device;
 253         int r;
 254
 255         assert(m);
 256
 257         if (device_for_action(d, SD_DEVICE_REMOVE) ||
 258             sd_device_has_current_tag(d, "seat") <= 0) {
 259                 const char *syspath;
 260
 261                 r = sd_device_get_syspath(d, &syspath);
 262                 if (r < 0)
 263                         return 0;
 264
 265                 device = hashmap_get(m->devices, syspath);
 266                 if (!device)
 267                         return 0;
 268
 269                 seat_add_to_gc_queue(device->seat);
 270                 device_free(device);
 271
 272         } else {
 273                 const char *sn, *syspath;
 274                 bool master;
 275                 Seat *seat;
 276
 277                 if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
 278                         sn = "seat0";
 279
 280                 if (!seat_name_is_valid(sn)) {
 281                         log_device_warning(d, "Device with invalid seat name %s found, ignoring.", sn);
 282                         return 0;
 283                 }
 284
 285                 seat = hashmap_get(m->seats, sn);
 286                 master = sd_device_has_current_tag(d, "master-of-seat") > 0;
 287
 288                 /* Ignore non-master devices for unknown seats */
 289                 if (!master && !seat)
 290                         return 0;
 291
 292                 r = sd_device_get_syspath(d, &syspath);
 293                 if (r < 0)
 294                         return r;
 295
 296                 r = manager_add_device(m, syspath, master, &device);
 297                 if (r < 0)
 298                         return r;
 299
 300                 if (!seat) {
 301                         r = manager_add_seat(m, sn, &seat);
 302                         if (r < 0) {
 303                                 if (!device->seat)
 304                                         device_free(device);
 305
 306                                 return r;
 307                         }
 308                 }
 309
 310                 device_attach(device, seat);
 311                 seat_start(seat);
 312         }
 313
 314         return 0;
 315 }
 316
 317 int manager_process_button_device(Manager *m, sd_device *d) {
 318         const char *sysname;
 319         Button *b;
 320         int r;
 321
 322         assert(m);
 323
 324         r = sd_device_get_sysname(d, &sysname);
 325         if (r < 0)
 326                 return r;
 327
 328         if (device_for_action(d, SD_DEVICE_REMOVE) ||
 329             sd_device_has_current_tag(d, "power-switch") <= 0) {
 330
 331                 b = hashmap_get(m->buttons, sysname);
 332                 if (!b)
 333                         return 0;
 334
 335                 button_free(b);
 336
 337         } else {
 338                 const char *sn;
 339
 340                 r = manager_add_button(m, sysname, &b);
 341                 if (r < 0)
 342                         return r;
 343
 344                 if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
 345                         sn = "seat0";
 346
 347                 button_set_seat(b, sn);
 348
 349                 r = button_open(b);
 350                 if (r < 0) /* event device doesn't have any keys or switches relevant to us? (or any other error
 351                             * opening the device?) let's close the button again. */
 352                         button_free(b);
 353         }
 354
 355         return 0;
 356 }
 357
 358 int manager_get_session_by_pid(Manager *m, pid_t pid, Session **ret) {
 359         _cleanup_free_ char *unit = NULL;
 360         Session *s;
 361         int r;
 362
 363         assert(m);
 364
 365         if (!pid_is_valid(pid))
 366                 return -EINVAL;
 367
 368         s = hashmap_get(m->sessions_by_leader, PID_TO_PTR(pid));
 369         if (!s) {
 370                 r = cg_pid_get_unit(pid, &unit);
 371                 if (r >= 0)
 372                         s = hashmap_get(m->session_units, unit);
 373         }
 374
 375         if (ret)
 376                 *ret = s;
 377
 378         return !!s;
 379 }
 380
 381 int manager_get_user_by_pid(Manager *m, pid_t pid, User **ret) {
 382         _cleanup_free_ char *unit = NULL;
 383         User *u = NULL;
 384         int r;
 385
 386         assert(m);
 387
 388         if (!pid_is_valid(pid))
 389                 return -EINVAL;
 390
 391         r = cg_pid_get_slice(pid, &unit);
 392         if (r >= 0)
 393                 u = hashmap_get(m->user_units, unit);
 394
 395         if (ret)
 396                 *ret = u;
 397
 398         return !!u;
 399 }
 400
 401 int manager_get_idle_hint(Manager *m, dual_timestamp *t) {
 402         Session *s;
 403         bool idle_hint;
 404         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 405
 406         assert(m);
 407
 408         idle_hint = !manager_is_inhibited(m, INHIBIT_IDLE, INHIBIT_BLOCK, t, false, false, 0, NULL);
 409
 410         HASHMAP_FOREACH(s, m->sessions) {
 411                 dual_timestamp k;
 412                 int ih;
 413
 414                 ih = session_get_idle_hint(s, &k);
 415                 if (ih < 0)
 416                         return ih;
 417
 418                 if (!ih) {
 419                         if (!idle_hint) {
 420                                 if (k.monotonic < ts.monotonic)
 421                                         ts = k;
 422                         } else {
 423                                 idle_hint = false;
 424                                 ts = k;
 425                         }
 426                 } else if (idle_hint) {
 427
 428                         if (k.monotonic > ts.monotonic)
 429                                 ts = k;
 430                 }
 431         }
 432
 433         if (t)
 434                 *t = ts;
 435
 436         return idle_hint;
 437 }
 438
 439 bool manager_shall_kill(Manager *m, const char *user) {
 440         assert(m);
 441         assert(user);
 442
 443         if (!m->kill_exclude_users && streq(user, "root"))
 444                 return false;
 445
 446         if (strv_contains(m->kill_exclude_users, user))
 447                 return false;
 448
 449         if (!strv_isempty(m->kill_only_users))
 450                 return strv_contains(m->kill_only_users, user);
 451
 452         return m->kill_user_processes;
 453 }
 454
 455 int config_parse_n_autovts(
 456                 const char *unit,
 457                 const char *filename,
 458                 unsigned line,
 459                 const char *section,
 460                 unsigned section_line,
 461                 const char *lvalue,
 462                 int ltype,
 463                 const char *rvalue,
 464                 void *data,
 465                 void *userdata) {
 466
 467         unsigned *n = ASSERT_PTR(data);
 468         unsigned o;
 469         int r;
 470
 471         assert(filename);
 472         assert(lvalue);
 473         assert(rvalue);
 474
 475         r = safe_atou(rvalue, &o);
 476         if (r < 0) {
 477                 log_syntax(unit, LOG_WARNING, filename, line, r,
 478                            "Failed to parse number of autovts, ignoring: %s", rvalue);
 479                 return 0;
 480         }
 481
 482         if (o > 15) {
 483                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 484                            "A maximum of 15 autovts are supported, ignoring: %s", rvalue);
 485                 return 0;
 486         }
 487
 488         *n = o;
 489         return 0;
 490 }
 491
 492 static int vt_is_busy(unsigned vtnr) {
 493         struct vt_stat vt_stat;
 494         int r;
 495         _cleanup_close_ int fd = -EBADF;
 496
 497         assert(vtnr >= 1);
 498
 499         /* VT_GETSTATE "cannot return state for more than 16 VTs, since v_state is short" */
 500         assert(vtnr <= 15);
 501
 502         /* We explicitly open /dev/tty1 here instead of /dev/tty0. If
 503          * we'd open the latter we'd open the foreground tty which
 504          * hence would be unconditionally busy. By opening /dev/tty1
 505          * we avoid this. Since tty1 is special and needs to be an
 506          * explicitly loaded getty or DM this is safe. */
 507
 508         fd = open_terminal("/dev/tty1", O_RDWR|O_NOCTTY|O_CLOEXEC);
 509         if (fd < 0)
 510                 return -errno;
 511
 512         if (ioctl(fd, VT_GETSTATE, &vt_stat) < 0)
 513                 r = -errno;
 514         else
 515                 r = !!(vt_stat.v_state & (1 << vtnr));
 516
 517         return r;
 518 }
 519
 520 int manager_spawn_autovt(Manager *m, unsigned vtnr) {
 521         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 522         char name[sizeof("autovt@tty.service") + DECIMAL_STR_MAX(unsigned)];
 523         int r;
 524
 525         assert(m);
 526         assert(vtnr >= 1);
 527
 528         if (vtnr > m->n_autovts &&
 529             vtnr != m->reserve_vt)
 530                 return 0;
 531
 532         if (vtnr != m->reserve_vt) {
 533                 /* If this is the reserved TTY, we'll start the getty
 534                  * on it in any case, but otherwise only if it is not
 535                  * busy. */
 536
 537                 r = vt_is_busy(vtnr);
 538                 if (r < 0)
 539                         return r;
 540                 else if (r > 0)
 541                         return -EBUSY;
 542         }
 543
 544         xsprintf(name, "autovt@tty%u.service", vtnr);
 545         r = sd_bus_call_method(
 546                         m->bus,
 547                         "org.freedesktop.systemd1",
 548                         "/org/freedesktop/systemd1",
 549                         "org.freedesktop.systemd1.Manager",
 550                         "StartUnit",
 551                         &error,
 552                         NULL,
 553                         "ss", name, "fail");
 554         if (r < 0)
 555                 return log_error_errno(r, "Failed to start %s: %s", name, bus_error_message(&error, r));
 556
 557         return 0;
 558 }
 559
 560 bool manager_is_lid_closed(Manager *m) {
 561         Button *b;
 562
 563         HASHMAP_FOREACH(b, m->buttons)
 564                 if (b->lid_closed)
 565                         return true;
 566
 567         return false;
 568 }
 569
 570 static bool manager_is_docked(Manager *m) {
 571         Button *b;
 572
 573         HASHMAP_FOREACH(b, m->buttons)
 574                 if (b->docked)
 575                         return true;
 576
 577         return false;
 578 }
 579
 580 static int manager_count_external_displays(Manager *m) {
 581         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 582         sd_device *d;
 583         int r, n = 0;
 584
 585         r = sd_device_enumerator_new(&e);
 586         if (r < 0)
 587                 return r;
 588
 589         r = sd_device_enumerator_allow_uninitialized(e);
 590         if (r < 0)
 591                 return r;
 592
 593         r = sd_device_enumerator_add_match_subsystem(e, "drm", true);
 594         if (r < 0)
 595                 return r;
 596
 597         FOREACH_DEVICE(e, d) {
 598                 const char *status, *enabled, *dash, *nn, *subsys;
 599                 sd_device *p;
 600
 601                 if (sd_device_get_parent(d, &p) < 0)
 602                         continue;
 603
 604                 /* If the parent shares the same subsystem as the
 605                  * device we are looking at then it is a connector,
 606                  * which is what we are interested in. */
 607                 if (sd_device_get_subsystem(p, &subsys) < 0 || !streq(subsys, "drm"))
 608                         continue;
 609
 610                 if (sd_device_get_sysname(d, &nn) < 0)
 611                         continue;
 612
 613                 /* Ignore internal displays: the type is encoded in the sysfs name, as the second dash
 614                  * separated item (the first is the card name, the last the connector number). We implement a
 615                  * deny list of external displays here, rather than an allow list of internal ones, to ensure
 616                  * we don't block suspends too eagerly. */
 617                 dash = strchr(nn, '-');
 618                 if (!dash)
 619                         continue;
 620
 621                 dash++;
 622                 if (!STARTSWITH_SET(dash,
 623                                     "VGA-", "DVI-I-", "DVI-D-", "DVI-A-"
 624                                     "Composite-", "SVIDEO-", "Component-",
 625                                     "DIN-", "DP-", "HDMI-A-", "HDMI-B-", "TV-"))
 626                         continue;
 627
 628                 /* Ignore ports that are not enabled */
 629                 if (sd_device_get_sysattr_value(d, "enabled", &enabled) < 0 || !streq(enabled, "enabled"))
 630                         continue;
 631
 632                 /* We count any connector which is not explicitly
 633                  * "disconnected" as connected. */
 634                 if (sd_device_get_sysattr_value(d, "status", &status) < 0 || !streq(status, "disconnected"))
 635                         n++;
 636         }
 637
 638         return n;
 639 }
 640
 641 bool manager_is_docked_or_external_displays(Manager *m) {
 642         int n;
 643
 644         /* If we are docked don't react to lid closing */
 645         if (manager_is_docked(m)) {
 646                 log_debug("System is docked.");
 647                 return true;
 648         }
 649
 650         /* If we have more than one display connected,
 651          * assume that we are docked. */
 652         n = manager_count_external_displays(m);
 653         if (n < 0)
 654                 log_warning_errno(n, "Display counting failed: %m");
 655         else if (n >= 1) {
 656                 log_debug("External (%i) displays connected.", n);
 657                 return true;
 658         }
 659
 660         return false;
 661 }
 662
 663 bool manager_is_on_external_power(void) {
 664         int r;
 665
 666         /* For now we only check for AC power, but 'external power' can apply to anything that isn't an internal
 667          * battery */
 668         r = on_ac_power();
 669         if (r < 0)
 670                 log_warning_errno(r, "Failed to read AC power status: %m");
 671
 672         return r != 0; /* Treat failure as 'on AC' */
 673 }
 674
 675 bool manager_all_buttons_ignored(Manager *m) {
 676         assert(m);
 677
 678         if (m->handle_power_key != HANDLE_IGNORE)
 679                 return false;
 680         if (m->handle_power_key_long_press != HANDLE_IGNORE)
 681                 return false;
 682         if (m->handle_suspend_key != HANDLE_IGNORE)
 683                 return false;
 684         if (m->handle_suspend_key_long_press != HANDLE_IGNORE)
 685                 return false;
 686         if (m->handle_hibernate_key != HANDLE_IGNORE)
 687                 return false;
 688         if (m->handle_hibernate_key_long_press != HANDLE_IGNORE)
 689                 return false;
 690         if (m->handle_reboot_key != HANDLE_IGNORE)
 691                 return false;
 692         if (m->handle_reboot_key_long_press != HANDLE_IGNORE)
 693                 return false;
 694         if (m->handle_lid_switch != HANDLE_IGNORE)
 695                 return false;
 696         if (!IN_SET(m->handle_lid_switch_ep, _HANDLE_ACTION_INVALID, HANDLE_IGNORE))
 697                 return false;
 698         if (m->handle_lid_switch_docked != HANDLE_IGNORE)
 699                 return false;
 700
 701         return true;
 702 }
 703
 704 int manager_read_utmp(Manager *m) {
 705 #if ENABLE_UTMP
 706         int r;
 707         _unused_ _cleanup_(utxent_cleanup) bool utmpx = false;
 708
 709         assert(m);
 710
 711         if (utmpxname(_PATH_UTMPX) < 0)
 712                 return log_error_errno(errno, "Failed to set utmp path to " _PATH_UTMPX ": %m");
 713
 714         utmpx = utxent_start();
 715
 716         for (;;) {
 717                 _cleanup_free_ char *t = NULL;
 718                 struct utmpx *u;
 719                 const char *c;
 720                 Session *s;
 721
 722                 errno = 0;
 723                 u = getutxent();
 724                 if (!u) {
 725                         if (errno == ENOENT)
 726                                 log_debug_errno(errno, _PATH_UTMPX " does not exist, ignoring.");
 727                         else if (errno != 0)
 728                                 log_warning_errno(errno, "Failed to read " _PATH_UTMPX ", ignoring: %m");
 729                         return 0;
 730                 }
 731
 732                 if (u->ut_type != USER_PROCESS)
 733                         continue;
 734
 735                 if (!pid_is_valid(u->ut_pid))
 736                         continue;
 737
 738                 t = strndup(u->ut_line, sizeof(u->ut_line));
 739                 if (!t)
 740                         return log_oom();
 741
 742                 c = path_startswith(t, "/dev/");
 743                 if (c) {
 744                         r = free_and_strdup(&t, c);
 745                         if (r < 0)
 746                                 return log_oom();
 747                 }
 748
 749                 if (isempty(t))
 750                         continue;
 751
 752                 s = hashmap_get(m->sessions_by_leader, PID_TO_PTR(u->ut_pid));
 753                 if (!s)
 754                         continue;
 755
 756                 if (s->tty_validity == TTY_FROM_UTMP && !streq_ptr(s->tty, t)) {
 757                         /* This may happen on multiplexed SSH connection (i.e. 'SSH connection sharing'). In
 758                          * this case PAM and utmp sessions don't match. In such a case let's invalidate the TTY
 759                          * information and never acquire it again. */
 760
 761                         s->tty = mfree(s->tty);
 762                         s->tty_validity = TTY_UTMP_INCONSISTENT;
 763                         log_debug("Session '%s' has inconsistent TTY information, dropping TTY information.", s->id);
 764                         continue;
 765                 }
 766
 767                 /* Never override what we figured out once */
 768                 if (s->tty || s->tty_validity >= 0)
 769                         continue;
 770
 771                 s->tty = TAKE_PTR(t);
 772                 s->tty_validity = TTY_FROM_UTMP;
 773                 log_debug("Acquired TTY information '%s' from utmp for session '%s'.", s->tty, s->id);
 774         }
 775
 776 #else
 777         return 0;
 778 #endif
 779 }
 780
 781 #if ENABLE_UTMP
 782 static int manager_dispatch_utmp(sd_event_source *s, const struct inotify_event *event, void *userdata) {
 783         Manager *m = ASSERT_PTR(userdata);
 784
 785         /* If there's indication the file itself might have been removed or became otherwise unavailable, then let's
 786          * reestablish the watch on whatever there's now. */
 787         if ((event->mask & (IN_ATTRIB|IN_DELETE_SELF|IN_MOVE_SELF|IN_Q_OVERFLOW|IN_UNMOUNT)) != 0)
 788                 manager_connect_utmp(m);
 789
 790         (void) manager_read_utmp(m);
 791         return 0;
 792 }
 793 #endif
 794
 795 void manager_connect_utmp(Manager *m) {
 796 #if ENABLE_UTMP
 797         sd_event_source *s = NULL;
 798         int r;
 799
 800         assert(m);
 801
 802         /* Watch utmp for changes via inotify. We do this to deal with tools such as ssh, which will register the PAM
 803          * session early, and acquire a TTY only much later for the connection. Thus during PAM the TTY won't be known
 804          * yet. ssh will register itself with utmp when it finally acquired the TTY. Hence, let's make use of this, and
 805          * watch utmp for the TTY asynchronously. We use the PAM session's leader PID as key, to find the right entry.
 806          *
 807          * Yes, relying on utmp is pretty ugly, but it's good enough for informational purposes, as well as idle
 808          * detection (which, for tty sessions, relies on the TTY used) */
 809
 810         r = sd_event_add_inotify(m->event, &s, _PATH_UTMPX, IN_MODIFY|IN_MOVE_SELF|IN_DELETE_SELF|IN_ATTRIB, manager_dispatch_utmp, m);
 811         if (r < 0)
 812                 log_full_errno(r == -ENOENT ? LOG_DEBUG: LOG_WARNING, r, "Failed to create inotify watch on " _PATH_UTMPX ", ignoring: %m");
 813         else {
 814                 r = sd_event_source_set_priority(s, SD_EVENT_PRIORITY_IDLE);
 815                 if (r < 0)
 816                         log_warning_errno(r, "Failed to adjust utmp event source priority, ignoring: %m");
 817
 818                 (void) sd_event_source_set_description(s, "utmp");
 819         }
 820
 821         sd_event_source_unref(m->utmp_event_source);
 822         m->utmp_event_source = s;
 823 #endif
 824 }
 825
 826 void manager_reconnect_utmp(Manager *m) {
 827 #if ENABLE_UTMP
 828         assert(m);
 829
 830         if (m->utmp_event_source)
 831                 return;
 832
 833         manager_connect_utmp(m);
 834 #endif
 835 }
 836
 837 int manager_read_efi_boot_loader_entries(Manager *m) {
 838 #if ENABLE_EFI
 839         int r;
 840
 841         assert(m);
 842         if (m->efi_boot_loader_entries_set)
 843                 return 0;
 844
 845         r = efi_loader_get_entries(&m->efi_boot_loader_entries);
 846         if (r == -ENOENT || ERRNO_IS_NOT_SUPPORTED(r)) {
 847                 log_debug_errno(r, "Boot loader reported no entries.");
 848                 m->efi_boot_loader_entries_set = true;
 849                 return 0;
 850         }
 851         if (r < 0)
 852                 return log_error_errno(r, "Failed to determine entries reported by boot loader: %m");
 853
 854         m->efi_boot_loader_entries_set = true;
 855         return 1;
 856 #else
 857         return 0;
 858 #endif
 859 }